Flap folding apparatus



2 Sheets-Sheet 1 Filed July 1, 1959 a EI IA'IIT IIIIIIA INVENTOR K/c/Iara Mmf/zr and Karl" flan/16616;" BY

A TTOP/VEY May 7, 1963 R. WINKLER ETAL FLAP FOLDING APPARATUS 2 Sheets-Sheet 2 Filed July 1, 1959 INVENTOR. Ric/lard M'flk/er and Kari" Dunnexer MZMWu ATTOE/VEY United States Patent Ofi ice 3&88382 Patented May 7., 1963 3,088,382 FLAP FOLDING APPARATUS Richard Winkier, Rengsdorf, near Neuwied, and Kurt Dunnebier, Wollendorf, near Neuwied, Germany, as-

signors to Berkley Machine Company, Kansas City,

Mo., a corporation of Missouri Filed July 1, 1959, Ser. No. 824,279 4 Claims. (Cl. 93-62) This invention relates to rotary envelope making machines, and more particularly to a mechanism thereof for folding the bottom and closure flap portions of envelope blanks during processing of the blanks into envelopes.

The principal object of the invention is to provide a folding mechanism which simplifies the folding operations of the bottom and closure flaps, promotes greater speed and accuracy, and which results in a more compact and shorter envelope making machine.

Other objects of the invention are to provide a folding mechanism equipped with passes for manipulating the envelope blanks to utilize suction and pressure rollers for effecting folds of both the bottom and closure'flaps, and to provide improved means for separately removing and conveying the envelopes from the machine.

In accomplishing these and other objects of the invention as hereinafter pointed out, we have provided improved structure, the preferred form of which is illustrated in the accompanying drawings, wherein:

FIG. l is a longitudinal section of a bottom and closure flap folding mechanism embodying the features of the present invention, and which is adapted to form a part of a complete envelope making machine.

FIG. 2 is a fragmentary plan view of a first suction roller for initiating feed of the envelope blanks from the side flap folding and gumming section of the machine and delivering the blanks to the closure and bottom flap folding mechanism of the present invention.

FIG. 3 is a similar plan view of the suction roller which cooperates with a pressure roller of the mechanism to crease the fold of the bottom flap, and which seizes the closure flap to carry the blank into contact with a second pressure roller for creasing and folding the closure flap.

FIG. 4 is a fragmentary section through the first suction and pressure rollers and a portion of the pass into which the bottom flap is passed while the suction is carrying the blank into position under a guide roller for turning the bottom flap over the body portion of the blank. FIG. 5 is a similar section of the rollers shown in FIG. 4, with the blank being fed between pressure and suction rollers for completing the crease of the bottom foldj FIG. 6 is a similar section through the roller mechanism shown in FIG. 5, with the addition of the pass for receiving the partially folded blank, and the pressure roller which cooperates with the suction roller in folding the closure flap. 7

FIG. 7 is a section similar to FIG. 6, but showing the envelope deflected into the final pass and the vacuum roller in position to seize the closure flap.

FIG. 8 is a similar section, but showing the fold being made in the closure flap while the blank is being withdrawn from the final pass and carried between the suction roller and the cooperating pressure roller.

FIG. 9 is a similar section showing the envelope blank after the fold of the closure flap is completed and the blank is being delivered to the discharge mechanism of the apparatus.

FIG. 10 is a fragmentary perspective view to better illustrate the pushing fingers, the rock shaft, the rocker arm, and the cam which actuates the arm of the rock shaft. i

Referring more in detail to the drawings:

1 designates a bottom and closure flap folding mechanism embodying the features of the present invention and which forms a part of a complete envelope making machine. The envelope blanks a are delivered to the mechanism '1 with sealing gum 11 applied to the closure flap c and the side flaps d and e folded inwardly over the body portion 1 and provided with stripes of adhesive g and h thereon, the blanks being advanced with the bottom flaps i leading and the closure flaps trailing, as shown in FIG. 2. In order to simplify the illustrations, only those portions of the envelope making machine which pertain to feed of the blanks into the mechanism of the present invention are illustrated in the drawings. These are feed rollers 2 and 3, a horizontal support 4, and a roller 5 by which the gum stripes g and h are applied to the previously folded side flaps d and e.

The mechanism 1 which forms the present invention includes complementary rollers 6 and 7 to continue advance of the blanks, which guide the blanks therebetween at a substantially flat angle to carry the bottom flap portions i over a guide roller 8 and onto an inclined ramp 9 that deflects the bottom flap i of the envelope .to partially break upon the score line j, as best shown in .of the sections 10 and 11 and has a shape to provide a slot 15 that extends from the forward edge 16 of the arcuate face portion 13 around the roller to the trailing edge 17 and through which a jet of air is discharged from a nozzle 18 to assist in deflecting the bottom flap i of the blank upwardly over the roller 8'. The roller 6 constitutes a pressure roller having peripheral portions 19 for contacting the blank in offset relation with the gum stripes g and h to cooperate with the roller 7 in feeding the blanks therebetween.

The roller 7, in line with the arcuate face portion 13, is provided with a longitudinal series of oblong holes or suction ports 20. The roller 7 is timed so that the line of ports engage the body f of the blank along the trailing side of the score j to seize the body portion of the blank and grip the body of the blank thereto as the bottom flap i is deflected up the ramp 9. The suction is effective on the body of the blank to carry the seized portion of the body portion 7 of the blank therewith and under the roller 8, which cooperates with the peripheral face portions of the roller 7 in bending the bottom flap on the score j as the suction roller carries the body of the blank around the periphery thereof and into contact with the under side of the roller 8. The grip of the rollers 7 and 8 on the blank is now suflicient to continue the feed thereof, and the suction through the ports 20* is suspended so that the feed of the blank can continue upon a substantially horizontal guide 21 as the bottom flap is withdrawn from the ramp and laid over the inturned side flaps d and e. The roller 7 is preferably adjustable to position the suction ports circumferentially to set the most favorable position thereof in producing the bend along the score j and assure that the bend enters the pass between the rollers 7 and 8. In order to avoid double creasing of the fold th-us produced, the roller 8 preferably has only the function of receiving and folding the bottom flap i without pressing it against the adhesive on the side flaps. Therefore, there is always a space maintained between the roller 8 and suction roller 7 according to the paper thickness, which may be about .2 mm. with thin papers and up to .5 mm. with thick papers.

recess or notch 36'.

The feed of the blank continues across the guide 21 and the fold is passed between a pair of pressing rollers 22 and 23, which crease the fold and press the bottom flap into positive sealing contact with the adhesive on the side flaps. The blank continues between the rollers 22 and 23 into a pocket 24 which is formed between upwardly sloping slats 25 and superimposed guides 26. The roller 22 may be an ordinary covered pressure roller having a resilient covering, but the roller 23 is a vacuum roller and is provided with a longitudinal series of suction ports 27.

It is to be understood that with the roller arrangement previously described, the roller 8' has only a secondary function asa conveyor means, depending upon the roughness of the paper stock from which the envelopes are formed, and the blank is advanced substantially freely between the rollers 7 and 8 over the entire path until the fold formed by the score 1' engages the bight between the rollers 22 and 23. It is, therefore, clear that the blanks, measured from the fold line of the bottom flap i to the end of the closure flap c, must be at leastas long as the development of the track between the rollers 67 and 22r'23. Attention is also directed to the fact that the diameter of the roller 7 is a selected standard corresponding with a working cycle of the envelope making machine, and that the diameter of the roller 23 is onethird the diameter of the roller 7, and is, therefore, operated three times as fast as the roller 7. This necessitates suction through the ports 27 on each-third revolution to correspond with the working cycle, and this is effected as disclosed in our copending application Serial No. 824,282, filed even date herewith. The suction is timed so that it is effective immediately after the score k of the closure flap passes the ports 27 (FIG. 3), whereby the sealing flap c is seized and carried about the periphery of the suction roller 23 to a pressure roller 28. Oscillatory pushing fingers 29 stop movement of the blank into the pocket and act to reverse the direction of the feed, that is, to initiate a reverse thrust on the leading edge which cooperates with the suction grip of the roller 23 to buckle the blank downwardly so that the blank bends on the score k to start folding and creasing of the sealing flap as the fold passes between the rollers 23 and 28. Fromthe rollers 23 and 28, the finished envelopes pass over a guide 30 between the spirals 31 of a conveying-means 32, whereby the envelopes are pushed to the delivery table (not shown).

The fingers 29 are carried on a rock shaft 33 having a rocker arm 34 on one end thereof (FIGS. 1 and 10). The rocker arm carries a roller 35 rotatable thereon and in contact with the periphery of a cam 36, having a The rocker arm is connected to a spring 37 that holds the roller in contact with the cam. The entire unit, including the rock shaft 33, cam 36 and spring 37 is carried on a rack 38 which is adjustable upon the frame of the machine to adjust the position of the fingers 29. The unit is adjusted on the frame by a pini0n39 meshing with the teeth of the rack.

In order to hold the portions of the blanks which are under withdrawal from the ramp 9 and pocket 24 from contacting the rollers 6 and '22, dependingguards 40 and 41 may be provided, as shown in FIG. 1. V

The operation has "been described in connection with the description of the apparatus, but briefly the blanks :are delivered from other operating mechanisms'of the envelope making machine, for example, the seal flap! gumming mechanism, gum drying mechanism, side flap folding mechanism, and thelike, with the blanks being fed to the flap folding mechanism of the present invention between the feed rollers 2 and 3, with thebottom flap leading and the closure or sealing flap trailing, 'onto the horizontal guide 4, where the roller applies the gum stripes g and h to the intumed side flaps.

The blank is now in position where the feed rollers 6 and 7 engage the blank and advance the blank with the bottom flap being deflected by the guide roller 8 onto the ramp-9. As soon as the suction ports 20 come into contact with the trailing side of the score 1, the suction is made effective to seize the body f of the blank along the score i, as shown in FIG. 2. Continued movement of the rollers 6 and 7 then cause the body portion to be carried downwardly with the periphery of the sections 10 and 11 of the roller 7 and under the guide roller 8, while the bottom flap portion is drawn from around the guide roller 8 to the underside thereof for forming a downward buckle in the blank, which results in a fold along the score 1'. As above stated, the contact point of the rollers 6 and 7 continue advance of the blank across theguide substantially without aid of the guide roller 8 until the bottom fold is in position to be engaged by the creasing rollers 22 and 23. During this movement, the guide roller 8, being spaced from the periphery of the feed roller 7, permits the blank to pass thereunder without pressing the bottom flap 1' against the gum stripes g and 'h, and so that the gum, instead of being squeezed out from under the bottom fiap, has time to be sutficiently absorbed into the paper while an envelope is being advanced across the guide 21. As soon as the fold engages the creasing rollers 22 and 23, the closure flap passes from between the feed rollers 6 and 7, whereupon the creasing rollers take over to continue advance of the blank, creasing the fold, and pressing .the bottom flap into sealing contact with the gum on the side flaps. In this way, the gum has sufficiently penetrated into the fibers to make a solid seal before the bottom flap is creased and pressed to the side flaps. The folded edge, after passing the creasing rollers, makes contact with the ramp 25 and passes upwardly into the pocket 24 until the fold engages the fingers 29. At this time the suction ports of the lower creasing roller engage the sealing flap on the trailing side of the score k, whereupon the suction becomes effective to seize the closure flap and carry the closure flap downwardly toward the bight between the lower creasing roller and the pressure roller 28. During the start of this movement, the fingers 29 are actuated to exert thrust on the folded edge of the blank, so that these opposed forces start the fold on the score k, and as the fold is carried into contact with the pressure roller 28, the portion of the blank in the pocket 24 is withdrawn therefrom and fed downwardly between the pressure roller 28 and the creasing roller27 into contact with the vertical guide 30, wherecordance with the usual practice.

From the foregoing, it is obvious that we have provided a mechanism which is substantially compact and which effectively folds the bottom and closure flaps in a relatively short travel of the blanks.

What we claim and desire to secure by Letters Patent is:

1. A bottom flap folding mechanism for an envelope making machine in which the envelope blanks are delivered to the folding mechanism with side flaps folded and gummed and with the bottom flaps leading, said folding mechanism including upper and lower feed rollers in the path of the blanks for passing the blanks therebetween, a guide roller having a cylindrical surface with the upper portion thereof above the path of the blanks emerging from between the feed rollers for diverting the bottom flaps of the blanks upwardly over the guide roller, said lower feed roller having a peripheral portion spaced in fixed relation from the cylindrical surface of the guide roller to provide a pass therebetween according to the thickness of the blanks, a substantially flat guide means having one end extending under the guide roller to carry the blanks thereon away from said pass to allow absorption of the gum into the material of the blanks, and upper and lower creasing and pressing rollers separate from the .feed and guide rollers and located at the other end of the flat guide means, said portion of thelower feed roller having means for seizing a blank to initiate a fold in the bottom flap as the seized portion of the blank is carried downwardly under the guide roller and through said pass without pressing the bottom flap into firm sealing contact with the side flaps while the blank is pushed across the substantially flat guide means by the feed rollers for bringing the fold into engagement with the creasing and pressing rollers for creasing the fold and firmly pressing the bottom flap into sealing contact with the gummed side flaps.

2. A bottom flap folding mechanism for an envelope making machine in which the envelope blanks are delivered to the folding mechanism with side flaps folded and gummed and with the bottom flaps leading, said folding mechanism including upper and lower feed rollers in the path of the blanks for passing the blanks therebetween, a ramp in spaced relation with the feed rollers on the delivery side thereof, a guide roller in said space between the feed rollers and the lower end of the ramp and having a cylindrical surface with the upper portion thereof located across the path of the blanks emerging from the feed rollers for diverting the bottom flaps of the blanks upwardly over the feed roller onto the ramp, said lower feed roller having a peripheral portion spaced in fixed relation from the cylindrical surface of the guide roller to provide a pass therebetween according to the thickness of the blanks, a substantially flat guide means having one end extending under the guide roller to carry the blank thereon away from said pass to allow absorption of the gum into the material of the blanks, and upper and lower creasing and pressing rollers separate from the feed and guide rollers and located at the delivery end of the flat guide means, said portion of the lower feed roller having means for seizing .a blank to initiate a fold in the bottom flap as the seized portion of the blank is carried downwardly under the guide roller and onto the substantially flat guide means for withdrawing the bottom flap thereof from the ramp and around the guide roller into loose contact with the gum on the side flaps while the blank is pushed across the substantially flat guide means by the feed rollers for bringing the fold into engagement with the creasing and pressing rollers for pressing the bottom flap into firm sealing contact with the gum of the side flaps.

3. In a flap folding mechanism for an envelope making machine, upper and lower feed rollers in the path of the blanks for passing the blanks therebetween, a guide roller having a cylindrical surface with the upper portion thereof located above the path of the blanks emerging from the feed rollers for diverting a leading flap on the blanks, said lower feed roller having a peripheral recess across which the flap of said blanks move, a nozzle for discharging a jet of air through the recess and into contact with the flap for lifting the flap over the guide roller, said lower feed roller having a peripheral portion spaced in fixed relation from the cylindrical surface of the guide roller to provide a pass therebetween according to the thickness of the blanks, and means on the lower feed roller for seizing a blank to initiate a fold in the flap and for carrying the seized portion of the blank downwardly under the guide roller to make said initial fold and to draw the flap from over the guide roller.

4. A bottom flap folding mechanism for an envelope making machine in which the envelope blanks are delivered to the folding mechanism with side flaps folded and gummed and with the bottom flaps leading, said folding mechanism including upper and lower feed rollers in the path of the blanks for passing the blanks therebetween, a guide roller having cylindrical surface with the upper portion thereof above the path of the blanks emerg-- ing from the feed rollers for diverting the bottom flaps of the blanks upwardly over the guide roller, said lower feed roller having a peripheral portion spaced in fixed relation from the cylindrical surface of the guide roller to provide a pass therebetween according to the thickness of the blanks, a substantially flat guide means having a forward end extending under the guide roller, upper and lower creasing and pressing rollers separate from the feed and guide rollers and located at the delivery end of said guide means, said lower feed roller having a peripheral passageway transversely of the path of the blanks and across which the bottom flaps travel, and a nozzle for discharging a jet of air from said recess for lifting the bottom flaps onto the top of the guide roller, said peripheral portion of the lower feed roller having means for seizing a blank to initiate a fold in the bottom flap as the seized portion of the blank is carried downwardly under the guide roller and onto said guide means for withdrawing the bottom flap from across the top of the guide roller and through said pass without pressing the bottom flap into firm sealing contact with the side flaps while the blank is pushed across said guide means by the feed rollers for bringing the initial fold between the creasing and pressing rollers for pressing the bottom flap int-o firm sealing contact with the gummed side flaps.

References Cited in the file of this patent UNITED STATES PATENTS 1,807,867 Novick June 2, 1931 1,879,990 Oles Sept. 27, 1932 1,884,468 Winkler Oct. 25, 1932 1,985,859 Goder Dec. 25, 1934 2,143,715 Rosebush Jan. 10, 1939 2,244,723 Novick June 10, 1941 2,851,934 Heywood Sept. 16, 1958 2,944,470 Doetsch July 12, 1960 FOREIGN PATENTS 172,287 Germany June 21, 1906 

1. A BOTTOM FLAP FOLDING MECHANISM FOR AN ENVELOPE MAKING MACHINE IN WHICH THE ENVELOPE BLANKS ARE DELIVERED TO THE FOLDING MECHANISM WITH SIDE FLAPS FOLDED AND GUMMED AND WITH THE BOTTOM FLAPS LEADING, SAID FOLDING MECHANISM INCLUDING UPPER AND LOWER FEED ROLLERS IN THE PATH OF THE BLANKS FOR PASSING THE BLANKS THEREBETWEEN, A GUIDE ROLLER HAVING A CYLINDRICAL SURFACE WITH THE UPPER PORTION THEREOF ABOVE THE PATH OF THE BLANKS EMERGING FROM BETWEEN THE FEED ROLLERS FOR DIVERTING THE BOTTOM FLAPS OF THE BLANKS UPWARDLY OVER THE GUIDE ROLLER, SAID LOWER FEED ROLLER HAVING A PERIPHERAL PORTION SPACED IN FIXED RELATION FROM THE CYLINDRICAL SURFACE OF THE GUIDE ROLLER TO PROVIDE A PASS THEREBETWEEN ACCORDING TO THE THICKNESS OF THE BLANKS, A SUBSTANTIALLY FLAT GUIDE MEANS HAVING ONE END EXTENDING UNDER THE GUIDE ROLLER TO CARRY THE BLANKS THEREON AWAY FROM SAID PASS TO ALLOW ABSORPTION OF THE GUM INTO THE MATERIAL OF THE BLANKS, AND UPPER AND LOWER CREASING AND PRESSING ROLLERS SEPARATE FROM THE FEED AND GUIDE ROLLERS AND LOCATED AT THE OTHER END OF THE FLAT GUIDE MEANS, SAID PORTION OF THE LOWER FEED ROLLER HAVING MEANS FOR SEIZING A BLANK TO INITIATE A FOLD IN THE BOTTOM FLAP AS THE SEIZED PORTION OF THE BLANK IS CARRIED DOWNWARDLY UNDER THE GUIDE ROLLER AND THROUGH SAID PASS WITHOUT PRESSING THE BOTTOM FLAP INTO FIRM SEALING CONTACT WITH THE SIDE FLAPS WHILE THE BLANK IS PUSHED ACROSS THE SUBSTANTIALLY FLAT GUIDE MEANS BY THE FEED ROLLERS FOR BRINGING THE FOLD INTO ENGAGEMENT WITH THE CREASING AND PRESSING ROLLERS FOR CREASING THE FOLD AND FIRMLY PRESSING THE BOTTOM FLAP INTO SEALING CONTACT WITH THE GUMMED SIDE FLAPS. 